Problem: Is ${624340}$ divisible by $4$ ?
Answer: A number is divisible by $4$ if the last two digits are divisible by $4$ . [ Why? We can rewrite the number as a multiple of $100$ plus the last two digits: $ \gray{6243} {40} = \gray{6243} \gray{00} + {40} $ Because $624300$ is a multiple of $100$ , it is also a multiple of $4$ So as long as the value of the last two digits, ${40}$ , is divisible by $4$ , the original number must also be divisible by $4$ Is the value of the last two digits, $40$ , divisible by $4$ Yes, ${40 \div 4 = 10}$, so $624340$ must also be divisible by $4$.